1. Field
Embodiments of the present disclosure relate to an apparatus and method to control a brushless direct current (BLDC) motor, which may detect driving current flowing through coils of the BLDC motor and may prevent errors from occurring during detection of the driving current.
2. Description of the Related Art
Unlike a direct current (DC) motor in which a permanent magnet is installed on a stator and a coil is installed on a rotor and which changes current flowing through the coil via a commutator and a brush, a brushless direct current (BLDC) motor, which is configured in such a way that a permanent magnet is installed on a rotor and a coil is installed on a stator and no commutator and brush are required, rotates the rotor including the permanent magnet installed thereon through a continuous rotating field that is formed by changing driving current. In general, a pulse width modulator is used for the BLDC motor in order to change a driving voltage in response to a change in the driving current.
The pulse width modulator that is used to change the driving voltage in the BLDC motor repeats an on/off switching operation in which switching noise may occur. The switching noise is transferred to a BLDC motor driver and the BLDC motor. Thus, the switching noise is contained in the driving current, which is used to drive the BLDC motor.
In general, a control apparatus for the BLDC motor uses a current control loop to measure current input to the BLDC motor and to feedback the current to the controller in order to control a torque of the BLDC motor. The pulse width modulator to drive the BLDC motor and the current control loop operate independently from each other. In this regard, when the current control loop measures the driving current at a time that the driving voltage is changed by the pulse width modulator, switching noise occurs in the measured driving current, and then, the driving current containing the switching noise is detected.
For this reason, such a conventional BLDC motor control apparatus inaccurately detects current, resulting in a difficulty in accurate current control and degradation in control performance.